Stagnation Region Radiative Ablation of Asteroidal Meteoroids in the Rosseland Approximation

Abstract

The ablation rates of large iron-containing stony meteoroids are calculated at their stagnation point assuming the meteoroid to be spherical in shape. The flow is assumed to be thermochemically in equilibrium and inviscid. The Rosseland approximation is used in describing radiative transfer, using the Rosseland mean absorption coefficients determined previously by the present author. The calculation is performed for the range of freestream densities, velocities, and nose radii pertinent to meteoroid entry flights. The calculated ablation rates are smaller than the values calculated by Kosarev et al. ("Vapor Optical Properties and Ablation of Large Chondrite and Ice Bodies in The Earth's Atmosphere," Solar System Research, Vol. 30, No. 4, 1996, pp. 265-278) and Golub et al. ("Emission and Ablation of Large Meteoroid in the Course of Its Motion Through The Earth's Atmosphere," Solar System Research, Vol. 30, No. 3, 1996, pp. 183-197) and are only weakly dependent on the flight speed.